The effect of current reversal on two commercially manufactured electrodes (RuO2-TiO2 and IrO2-Ta2O5 coated Ti) in a chloride bearing electrolyte was evaluated. Accelerated lifetimes were found to decrease with increasing current density and increasing reversal frequency. Ru: Ti coated electrodes exhibited longer lifetimes than Ir: Ta coated electrodes even though they had one-third as much precious metal content. Chloride concentration did not affect lifetime in the range examined. Using energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS), the failure mode of the electrodes was determined to be coating dissolution leading ultimately to passivation by the presumed growth of a highly resistive oxide at the coating/substrate interface.
- Catalytic titanium anodes,
- Current reversal,
- IrO2-Ta2O5,
- Lifetimes,
- RuO2-TiO2
Available at: http://works.bepress.com/michael-moats/34/